“Shorts are still available (CCI would be the best bet), but avoid the longs, they are no better than the shorts and less accurate - a real turn of the century orphan cartridge.”
With all due respect, that is just nonsense. I take it that you are not a shooter, are you?
Perhaps not. Only 40 years or so.
Longs as opposed to long rifle cartridges are almost universally acknowledged to be the worst of the three.
Shorts are very accurate, and many fine target arms are chambered for them exclusively.
If you have evidence to the contrary I would be glad to hear it, and if I’m wrong, well I’ll say so.